The crystal mill, reputed to be one of the most photographed sites in Colorado, is historically known as the Sheep Mountain Power House or Lost Horse Mill. Built in 1893, the mill harnessed the power of the Crystal River to run its massive air compressor which, in turn, drove power to drills in the Sheep Mountain and Bear Mountain silver mines.
When the Sheep Mountain mine closed in 1917, the mill, too, was abandoned. It was decreed a landmark and put on the National Register of Historic Places on July 5th, 1985 and has been a standing skeleton ever since, just a quarter mile outside the ghost town of Crystal — a former silver mining camp established in 1880, which has never had (and still does not have) electricity, although it is home for a few inhabitants.